In a floor panel structure of a vehicle body in which a floor of an automotive vehicle is formed by a floor panel coupled to a plurality of frame members extending in substantially longitudinal and width directions of the vehicle, there are provided a panel area formed by being enclosed at least by the frame members, a heavy-weight area located at a substantially central portion of the panel area, and a peripheral area located substantially around the heavy-weight area, wherein the heavy-weight area is configured so as to be heavier than the peripheral area. Accordingly, the vibration energy transmitted from the frame members to the floor panel can be reduced and thereby the acoustic emission generated from the floor panel can be reduced.
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1. A floor panel structure of a vehicle body, in which a floor of an automotive vehicle is formed by a floor panel coupled to a plurality of frame members which extend in substantially longitudinal and width directions of the vehicle, comprising:
a panel area provided at said floor panel, said panel area being formed by being enclosed at least by said frame members,
a heavy-weight area formed within said panel area, said heavy-weight area comprising an application-type of damping material which is provided at the substantially central portion of said panel area, and an asphalt-based damping material is provided at a peripheral area formed within said panel area, having a lower hardness and a greater specific gravity than that of said application-type of damping material provided at said heavy-weight area, the heavy-weight area being located at a substantially central portion of said panel area, and the peripheral area being located substantially around said heavy-weight area,
wherein said heavy-weight area is configured so as to be heavier than said peripheral area.
2. The floor panel structure of
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The present invention relates to a floor panel structure of a vehicle body, particularly to a floor panel structure of a vehicle body in which a floor of an automotive vehicle is formed by a floor panel coupled to a plurality of frame members which extend in substantially longitudinal and width directions of the vehicle body.
It is known that vibration from frame members coupled to the engine or the suspension of the vehicle is transmitted to floor panels and makes the floor panels and air in the cabin vibrate, resulting in uncomfortable vibration and noises being generated in the cabin. Herein, the vibration of engine itself and the road noise from the suspension are considered as vibration resources primarily. The road noise is generally caused by resonance of vehicle tires and sympathetic vibration of the suspension.
Conventionally, damping materials or the like which are applied to the floor panels or the particular portions of the vehicle body have been generally used to suppress such vibration and noises. However, a large amount of these materials are generally required, and thereby the weight of the vehicle body tends to increase improperly. This overweight would cause various disadvantages including an issue of costs.
Meanwhile, in view of facts that the frequency of uncomfortable vibration transmitted from the engine and suspension in the automotive vehicle is generally less than 400 Hz and particularly the peak of road noises exists at around 250 Hz which is caused by the resonance of vehicle tires, it is also known that the peculiar frequency of floor panels can be shifted to a high frequency band more than 400 Hz by increasing the rigidity of floor panels with many beads formed at the panels or thicker panels. Namely, the uncomfortable vibration and noises can be suppressed, by preventing the floor panels from vibrating sympathetically with the suspension or the vehicle tires.
In this case, however, the vibration with relatively high frequency tends to increase improperly instead. Accordingly, in order to suppress properly the increased vibration with relatively high frequency at the same time, additional damping materials or the like which should be useful to such vibration with high frequency would be also required. Accordingly, the same problems as described above would occur inevitably.
Meanwhile, Japanese Patent Laid-Open Publication No. 6-107235 discloses a panel structure of a vehicle body in which a panel comprises a plurality of projecting portions with shell structure, which has a proper strength in bending, compressing and tensioning, and recess portions extending between the projecting portions. Herein, the vibration generated could be increased at the recess portions primarily, and the increased vibration could be reduced properly by damping materials provided at the recess portions.
In general, since the exhaust pipe, various auxiliary parts and the like are disposed below or on the floor panel, the above-described projecting portions formed at the floor are required to be disposed with their proper height and location which will not interference with these objects. Further, the height of the projecting portions needs to be set properly so as to provide the passengers with comfortable stepping. Also, those projecting portions need to be formed properly within floor panels enclosed by the frame members. However, in view of these limitations in vehicle-body structure or manufacturing, there exists some cases where the vehicle body panel structure disclosed in the above-described patent publication could not reduce the vibration properly.
The present invention has been devised in view of the above-described problems of the conventional structure, and an object of the present invention is to provide a floor panel structure of a vehicle body which can reduce properly the vibration energy transmitted from the frame members to the floor panel and thereby reduce the acoustic emission generated from the floor panel.
According to the present invention, there is provided a floor panel structure of a vehicle body, in which a floor of an automotive vehicle is formed by a floor panel coupled to a plurality of frame members which extend in substantially longitudinal and width directions of the vehicle, comprising a panel area provided at the floor panel, the panel area being formed by being enclosed at least by the frame member, a heavy-weight area formed within the panel area, the heavy-weight area being located at a substantially central portion of the panel area, a peripheral area formed within the panel area, the peripheral area being located substantially around the heavy-weight area, wherein the heavy-weight area is configured so as to be heavier than the peripheral area.
According to this structure, since the heavy-weight area being heavier than the peripheral area is formed at the substantially central portion of the panel area, the vibration energy can be properly increased at the peripheral area due to the difference in weight between the heavy-weight area and the peripheral area. The vibration energy greatly and properly increased at the peripheral area is transformed to the heat energy by the damping function of the material which forms the floor panel. As a result, the vibration energy of the panel area can be reduced, and thereby the acoustic emission generated from the panel area can be reduced. Accordingly, regardless of the above-described limitations in the vehicle-body structure, such as height, locations, size and the like, or manufacturing, the vibration energy at the panel area can be reduced effectively by providing the heavy-weight area being heavier than the peripheral area.
According to a preferred embodiment of the present invention, the heavy-weight area comprises a plate which is thicker than that of the peripheral area, whereby the heavy-weight area is configured so as to be heavier than the peripheral area. According to this structure, since the heavy-weight area comprises the plate which is thicker than that of the peripheral area, the weight of the heavy-weight area can be increased easily and properly to provide the difference in weight between the heavy-weight area and the peripheral area. As a result, the vibration energy can be increased surely at the peripheral area, and thereby the vibration can be reduced. Further, since the heavy-weight area with the thicker plate is also increased in its rigidity, the vibration energy can be increased more intensively at the peripheral area by the difference in rigidity between the heavy-weight area and the peripheral area, and thereby the vibration energy can be reduced effectively.
According to another preferred embodiment of the present invention, the heavy-weight area comprises an opening portion which includes a through hole and a plug which is applied so as to close the through hole, and the plug comprises a plate which is thicker than the floor panel comprising the peripheral area. According to this structure, since the heavy-weight area comprises the plug applied to the through hole and the weight of the heavy-weight area is adjustable by controlling the thickness of the plug, the weight of the heavy-weight area can be increased easily and properly, so that the vibration energy can be increased surely at the peripheral area.
According to another preferred embodiment of the present invention, the opening portion further comprises a difference-in-level portion which projects downward, and the through hole is formed at the difference-in-level portion. According to this structure, since the through hole is formed at the difference-in-level portion projecting downward, for example, excessive paints can be easily and properly drained from the through hole in painting manufacturing process of the vehicle.
According to another preferred embodiment of the present invention, the plug includes a peripheral edge projection which projects at a periphery thereof upward or downward. According to this structure, since the rigidity of the plug is increased by the peripheral edge projection, the vibration energy can be increased more intensively at the peripheral area by this difference in rigidity between the heavy-weight area and the peripheral area.
According to another preferred embodiment of the present invention, the plug includes beads which are provided at an upper face thereof. According to this structure, since the rigidity of the plug is increased by the beads, the vibration energy can be increased more intensively at the peripheral area by the difference in rigidity between the heavy-weight area and the peripheral area as well.
According to another preferred embodiment of the present invention, the heavy-weight area comprises a damping material which is provided at the substantially central portion of the panel area, whereby the heavy-weight area is configured so as to be heavier than the peripheral area. According to this structure, since the heavy-weight area is constituted by the damping material provided at the substantially central portion of the panel area, the weight of the heavy-weight area can be easily increased to provide the difference in weight between the heavy-weight area and the peripheral area. As a result, the vibration energy can be increased surely at the peripheral area, and thereby the vibration can be reduced. Also, the vibration energy can be further reduced by the vibration damping function of the damping material itself.
According to another preferred embodiment of the present invention, the damping material comprises an application-type of damping material. According to this structure, since the application-type of damping material has a relatively high hardness and thus its hardness is relatively high, the rigidity of the heavy-weight area can be easily and properly increased. As a result, the vibration energy can be increased more intensively at the peripheral area by the difference in rigidity between the heavy-weight area and the peripheral area and thereby the vibration energy can be reduced effectively.
According to another preferred embodiment of the present invention, the damping material comprises an asphalt-based damping material. According to this structure, since the asphalt-based damping material has a relatively great specific gravity and thus its weight is relatively large, the weight of the heavy-weight area can be easily and properly increased. As a result, the difference in weight between the heavy-weight area and the peripheral area can be increased.
According to another preferred embodiment of the present invention, the heavy-weight area comprises the application-type of damping material which is provided at the substantially central portion of the panel area, and the asphalt-based damping material is provided at the peripheral area having a lower hardness and a greater specific gravity than that of the application-type of damping material provided at the heavy-weight area, whereby the heavy-weight area is configured so as to be heavier than the peripheral area. According to this structure, the vibration energy at the panel area can be further reduced by the vibration damping function of the application-type of damping material and the asphalt-based damping material themselves. Also, since the heavy-weight area comprises the application-type of damping material having higher rigidity and the asphalt-based damping material having lower rigidity is provided at the peripheral area, the difference between the rigidity of heavy-weight area and the rigidity of both the peripheral area and asphalt-based damping material can be provided easily and properly. Thus, the vibration energy can be further reduced by the vibration reduction effect by the difference in rigidity. Accordingly, where that the weight of the heavy-weight area is configured so as to be heavier than the peripheral area with the asphalt-based damping material, by making the application-type of damping material having relatively smaller specific gravity thicker than the asphalt-based damping material having relatively greater specific gravity, the vibration energy can be reduced by the vibration reduction effect by the difference in weight between the heavy-weight area and the peripheral area with the asphalt-based damping material.
According to another preferred embodiment of the present invention, the heavy-weight area comprises an auxiliary component which is attached thereto, whereby the heavy-weight area is configured so as to be heavier than the peripheral area. Accordingly, the weight of the heavy-weight area can be increased easily and properly by the auxiliary component to provide the difference in weight between the heavy-weight area and the peripheral area.
Other features, aspects, and advantages of the present invention will become apparent from the following description which refers to the accompanying drawings.
Hereinafter, preferred embodiments of the present invention will be described referring to the accompanying drawings.
First, the frame members will be described referring to
A pair of front side frames 18 having a closed cross section is provided at the front portion of the underbody 1 of the vehicle so as to extend in the longitudinal direction and enclose an engine room from the both sides. A No. 1 cross member 26 having a closed cross section, a reinforced member extending in the vehicle width direction, is connected to front ends of the front side frames 18. Further, to the front side frames are respectively attached an engine 40 and a front suspension cross member 42, and front suspensions 44 are supported at the front suspension cross member 42.
To rear ends of the front side frames 18 is coupled a No. 2 cross member 27 which extends in the vehicle width direction at a front end portion of the floor portion of the vehicle body. The No. 2 cross member 27 is attached to a lower slant portion of a dash panel (not illustrated) which separates the cabin from the engine room, and comprises a pair of torque box members 27a having a closed cross section which is disposed outside the front side frames 18, and a dash lower cross member 27b having a closed cross section which is disposed between the front side frames 18. The above-described side sills 20, floor side frames 22 and rear side frames 24, which respectively extend in the longitudinal direction as reinforcing members, axe provided at a floor portion in back of the No. 2 cross member 27.
The side sills 20 have a closed cross section, and front ends of the side sills 20 are coupled to the both ends of the No. 2 cross member 27. Inner edge portions of the side sills 20 are curved inward at a region from their substantially medium portions located between the No. 3 cross members 28 and the No. 4 cross members 29 to their portions located at the No. 4 cross members 29. Also, to the side sills are connected lower end portions of pillars 35 which extend upward, and upper end portions of the pillars 35 are connected to a vehicle roof.
Between these side sills 20 are respectively provided the floor side frames 22 having a U-shaped cross section, and the front ends of the floor side frames 22 are coupled to rear end portions of the front side frames 18 and the No. 2 cross member 27. The floor side frames 22 are curved inward at portions 22a between the No. 3 cross member 28 and the No. 4 cross member 29. Further, the floor side frames 22 are bent in the vehicle width direction at connecting portions 29a with the No. 4 cross member 29 and connecting portion 30a with the No. 5 cross member 30, respectively. Other portions of the floor side frames 22 extend substantially straight.
Front end portions of the rear side frames 24 having a U-shaped cross section are coupled to respective rear end portions of the floor side frames 22. Also, respective front end portions of the rear side frames 24 are bent outward and also connected to inside faces of the side sills 20. At these front end portions are provided reinforcing members 24a extending in the vehicle width direction. These rear side frames 24 extend to rear end edge portions of the floor portion, and a rear suspension cross member 46 is attached thereto between a No. 7 cross member 32 and a No. 8 cross member 33. Rear suspensions 48 are supported at the rear suspension cross member 46.
In addition to the above-described No. 1 cross member 26 and No. 2 cross member 27, there are provided the No. 3 through No. 8 cross members 28 through 33 having the U-shaped cross section, and a No. 9 cross member 34 having a closed cross section, as reinforcing members extending in the vehicle width direction. The No. 3 cross member 28 is provided in back of the No. 2 cross member 27 and extends substantially straight in the vehicle width direction, in parallel to the No. 2 cross member 27. The No. 3 cross member 28 is coupled to the side sills 20 at both end portions, and passes across the floor side frames 22 at the both sides and are connected thereat.
In back of the No. 3 cross member 28 is provided the No. 4 cross member which extends in the vehicle direction straight in parallel to the No. 3 cross member 28. The lateral both end portions of the No. 4 cross member 29 are connected to the side sills 20 near the pillars 35, respectively, and there is provided a low-rigidity area 110, which will be described below, near this portion. Also, the No. 4 cross member 29 crosses the floor side frames 22 at its lateral both ends and are connected to the floor side frames 22. These No. 3 and No. 4 cross members 28 and 29 project upward at the central portion where a floor tunnel portion 50.
The No. 5 cross member 30, No. 6 cross member 31 and No. 7 cross member 32 are provided in back of the No. 4 cross member 29, and these cross members 30, 31 and 32 extend substantially straight in the vehicle width direction, in parallel to each other. Both end portions of the No. 5 cross member 30 are coupled to the floor side frames 22, and respective both ends of the No. 6 and No. 7 cross members 31 and 32 are coupled to the rear side frames 24. In back of the No. 7 cross member 32 is provided the No. 8 cross member 33 which is curved forward at its central portion so as to extend in the vehicle width direction. And, both end portions of the No. 8 cross member 33 are coupled to the rear side frames 24, respectively. Further, behind the No. 8 cross member 33 is provided the No. 9 cross member 34 having the closed cross section which extend substantially straight in the vehicle width direction at the rear end edge portion of the floor portion. Both end portions of the No. 9 cross member 34 are coupled to rear end portions of the rear side frames 24, respectively.
In addition to the above-described front side frames 18, side sills 20, floor side frames 22 and rear side frames 24, there are provided No. 1 through No. 3 tunnel side members 36 through 38 having the U-shaped cross section which respectively extend in the longitudinal direction at both-side edge portions of the floor tunnel portion 50, as reinforcing members extending in the vehicle width direction. The No. 1 tunnel side members 36 extend substantially straight between the No. 2 cross member 27 and the No. 3 cross member 28, and its both end portions are coupled to the cross members 27 and 28, respectively.
The No. 2 tunnel side members 37 extends substantially straight between the No. 4 cross member 29 and the No. 5 cross member 30, and its both end portions are coupled to the cross members 29 and 30, respectively. The No. 3 tunnel side member 38 extend substantially straight between the No. 6 cross member 31 and the No. 7 cross member 32, and its both end portions are coupled to the cross members 31 and 32, respectively.
The above-described frame members having the U-shaped cross section, i.e., the floor side frames 22, rear side frames 24, No. 3 through No. 8 cross members 28 through 33 and No. 1 through No. 3 tunnel side members 36 through 38, are provided in such a manner that their open ends of the U-shaped cross section are directed upward and their flange portions are fixed to respective lower faces of the floor panels 2, 4, 6, 8, 10, 12, 14 and 16 to form substantially rectangular closed cross sections thereby.
Next, the floor panel will be described referring to
Further, there are provided bent line portions 52 on the first floor panel 2 at both sides of the floor tunnel portion 50, which extend substantially straight in the vehicle width direction in parallel to the No. 2 cross member 27 and No. 3 cross member 28. The bent line portions 52 are formed by bending the first floor panel 2 in the longitudinal direction at a specified angle with a straight bending line. At the first floor panel 2 are formed eight panel area S1 through S8 which are enclosed by the frame members 20, 22, 27, 28 and 36 and the bent line portions 52. The panel area S5 through S8 extend backward and upward, i.e., obliquely, from the panel area S1 through S4.
The second floor panel 4 is provided so as to cover an area enclosed by the No. 3 cross member 28, side sills 20 and No. 4 cross member 29, and its central portion projects upward to form the floor panel portion 50 extending in the longitudinal direction. The second floor panel 4 is coupled to the No. 3 cross member 28, side sills 20 and No. 4 cross member 29 at lower faces of edge portions at its four sides, respectively. Further, lower faces of both sides of the second floor panel 4 are coupled to the floor side frame 22, respectively.
Also, there are provided bent line portions 54 having a straight bending line at both edge portions of the floor tunnel portion 50 on the second floor panel 4. The floor tunnel portion 50 rises from the bent line portions. Further, on the second floor panel 4 are provided beads 56 which extend substantially straight along and at both sides of the above-described curved portions 22a of the floor side frames 22. The beads 56 extend from the No. 3 cross member 28 to the No. 4 cross member 29. At the second floor panel 4 are formed four panel area S9 through S12 which are enclosed by the frame members 20, 22, 28 and 29, the bent line portions 54 and the beads 56.
The third floor panel 6 is provided so as to cover an area enclosed by the No. 4 cross member 29, floor side frames 22 and No. 5 cross member 30, and its central portion projects upward to form the floor panel portion 50 extending in the longitudinal direction. The third floor panel 6 is coupled to the No. 4 cross member 29, floor side frames 22 and No. 5 cross member 30 at lower faces of edge portions at its four sides, respectively. Further, lower faces of both sides of the third floor panel 6 are coupled to the No. 2 tunnel side member 37, respectively.
Further, there are provided beads 58 on the third floor panel 6 at both sides of the floor tunnel portion 50, which extend substantially straight in the vehicle width direction in parallel to the No. 4 cross member 29 and No. 5 cross member 30. The beads 58 are formed by projecting part of the third floor panel 6 upward. At the third floor panel 6 are formed four panel area S13 through S16 which are enclosed by the frame members 22, 29, 30 and 37, and the beads 58.
The fourth floor panel 8 is provided outside the third floor panel 6 and extend in the longitudinal direction so as to cover an area enclosed by the No. 4 cross member 29, side sills 20, floor side frames 22 and rear side frames 24, and its rear edge portion extends near the No. 8 cross member 33. The fourth floor panel 8 is coupled to the respective frame members 20, 22, 24 and 29. The fifth floor panel 10 is provided so as to cover an area enclosed by the No. 5 cross member 30, No. 6 cross member 31, floor side frames 22 and rear side frames 24. The fifth floor panel 10 is coupled to the frame members 22, 24, 30 and 31 at lower faces of edge portions at its four sides, respectively.
The sixth floor panel 12 is provided so as to cover an area enclosed by the No. 6 cross member 31, No. 7 cross member 32 and rear side frames 24. The sixth floor panel 12 is coupled to the frame members 24, 31 and 32 at lower faces of edge portions at its four sides, respectively. The seventh floor panel 14 is provided so as to cover an area enclosed by the No. 7 cross member 32, No. 8 cross member 33 and rear side frames 24. The seventh floor panel 12 is coupled to the frame members 24, 32 and 33 at lower faces of edge portions at its four sides, respectively. The eighth floor panel 16 is provided so as to cover an area enclosed by the No. 8 cross member 33, No. 9 cross member 34 and rear side frames 24. The eighth floor panel 16 is coupled to the frame members 24, 33 and 34 at lower faces of edge portions at its four sides, respectively.
At the underbody 1 of the automotive vehicle described above, vibration of the engine 40, front suspension 44 and rear suspension 48 is transmitted to the floor side frames 22 and rear side frames 24 via the front suspension cross member 42, front side frames 18 and rear suspension cross member 46, and then to the cross members 26 through 34, side sills 20 and tunnel side members 36 through 38. The transmitted vibration is further transmitted to the first through eighth floor panels 2, 4, 6, 8, 10, 12, 14 and 16, thereby generating acoustic emission.
The first through third embodiments of the present invention are to suppress the noise generated from the panel area S1 through S4, S9, S12, S13 through S16 of the first through third floor panels 2, 4 and 6, which is caused by the vibration transmitted from the frame members, by providing a vibration reduction structure respectively at those panel area.
Herein, the vibration reduction structure of the vehicle body according to the present embodiments comprises a high-rigidity and/or heavy-weight area (high-rigidity area, heavy-weight area) and a low-rigidity and/or light-weight area (low-rigidity area, light-weight area, peripheral area) which are provided at specified area of the floor panels which are enclosed by the frame members and the like. The vibration energy transmitted to this area is increased at the low-rigidity area (the peripheral area) and/or the light-weight area (the peripheral area) due to the difference in rigidity between the high-rigidity area and the low-rigidity area, and/or the difference in weight between the heavy-weight area and the light-heavy area. This increased vibration energy causes a large vibration strain, and this large vibration strain produces a high vibration damping effect by a vibration damping function of a material (for example, steel plate) which forms the floor panel. Accordingly, the vibration can be reduced effectively. Thus, the acoustic emission generated from the respective area is reduced effectively by the vibration reduction structure.
Also, according to the fourth embodiment of the present invention, the vibration transmission reduction structure is provided at the No. 4 cross member 29 which is connected to the side sill 20. Accordingly, the vibration transmitted to the panel area S10, S11, S13 and S14 from the side sill 20 via the No. 4 cross member 29 is reduced. There are also provided the above-described vibration reduction structure at the panel area S10 and S11.
Herein, the vibration transmission reduction structure will be described. The vibration transmission reduction structure is that a specified low-rigidity area having a low rigidity is provided near a connecting portion of the cross member with the side frames, such as the side sill 20, floor side frame 22 and rear side frame. The side frame generally generates a torsional vibration with deformation to be slant laterally and or a bending vibration with a deformation to be bent longitudinally, and thereby the low-rigidity area at the cross member tends to be deformed easily. Thus, the vibration transmitted from the side frame tends to be increased at the low-rigidity area intensively. Accordingly, the vibration will be suppressed from being transmitted toward the inside of the vehicle from the low-rigidity area, and the vibration transmitted to the respective panel area from the cross member is reduced properly. As a result, the acoustic emission generated from the respective floor area is reduced. Herein, the panel area S5 through S8 and the fourth through eighth floor panels 8, 10, 12, 14 and 16 are formed by the conventional panel.
At first, the first embodiment of the present invention will be described specifically referring to
First, the constitution and shape of the panel area S1, S4, S9 and S12 will be described specifically referring to
Also, as illustrated in
Next, the vibration reduction structure provided at the panel area S1 will be described specifically referring to
The plug 66 is made of a circular steel plate which is large enough to close the through hole 64 at the opening portion 60 through the press forming, as illustrated in
The excessive paints of cation painting in painting the floor panel is drained out of the through hole 64. Since the through hole 64 is formed at the difference-in-level portion 62 projecting downward, the excessive paints can be drained easily and properly. After paining, the plug 66 is fixed firmly to the floor panel so as to close the through hole firmly by an adhesive 68. Also, there is provided a seal member 70 between the periphery of the plug 66 and the outer peripheral portion 62a of the difference-in-level portion 62. Herein, the adhesive 68 may also function as the seal member 70, and the plug 66 may be fixed by welding.
In the present embodiment, the above-described opening portion 60 and the plug 66 constitute the high-rigidity area (heavy-weight area) 72, and the peripheral area of the opening area 60 and plug 66 constitute the low-rigidity area (light-weight area) 74. The border between the high-rigidity area 72 and the light-rigidity area 74 is the portion a of the difference-in-level portion 62. Herein, the difference-in-level portion 62 may not be formed necessarily. Namely, the through whole 64 may be formed at a flat portion of the floor panel 2, and the plug 66 may be fixed so as to close this through hole 64. In this case, the peripheral portion of the plug 66 would be the border between the high-rigidity area 72 and the low-rigidity area 74. Also, this through hole 64 may function as a hole for positioning the floor panel in the press forming.
As illustrated in
Herein, an asphalt-based damping material with an approximately 1.7 specific gravity; an approximately 6B pencil-hardness (product name: Damping sheet by Hirotani Corporation) may be applied as the above-described damping material 76. The thickness of the damping material 76 is configured such that the total rigidity of the damping material 76 and the low-rigidity area 74 is lower than the rigidity of the high-rigidity area 72, i.e., the total rigidity of the opening portion 60 and the plug 66.
Next, a modified example of the plug 66 will be described referring to
Next, the function and effect of the floor panel structure according to the first embodiment will be described. Since the high-rigidity area 72 comprising the plug 66 and the opening portion 60 and the low-rigidity area 74 being provided around the high-rigidity area 72 are formed within the panel area S1, S4, S9 and S12 of the floor panel structure, the vibration energy is increased at the low-rigidity area 74 due to the difference in rigidity between the high-rigidity area 72 and the low-rigidity area 74. Further, since the high-rigidity area 72 also constitutes the heavy-weight area 72 which is made heavier per unit area than the low-rigidity area 74 by the plug 66 and the low-rigidity area 74 also constitutes the light-weight area (the peripheral area) 74, the vibration energy is further increased at the light-weight area (the peripheral area) 74 due to this difference in weight between the heavy-weight area 72 and the light-weight area 74.
The vibration energy being properly increased at the low-rigidity area (light-weight area) 74 is transformed to the thermal energy by the damping effect of the steel plate forming the floor panel 2 and 4. Thus, the vibration energy at the panel area S1, S4, S9 and S12 is reduced, and thereby the acoustic emission generated from the panel area is reduced. Further, since the damping material 76 is provided at the low-rigidity area (light-weight area) 74, the vibration energy being increased at the low-rigidity area (light-weight area) 74 is further reduced.
Next, the function and effect of the opening area 60 and the plug 66, which constitute the high-rigidity area (heavy-weight area) 72, will be described. Since the high-rigidity area (heavy-weight area) 72 comprises the opening area 60 for draining the excessive cation paints and the plug 66 applied to the opening area 60, that draining can be attained easily and the high-rigidity area (heavy-weight area) 74 having properly increased rigidity and weight by the plug 66, which is applied to the opening area 60 after that, can be obtained properly.
Also, since the plug 66 is formed separately from the floor panels 2 and 4, its rigidity can be increased appropriately. In the present embodiment, the plug 66 is configured so as to be thicker than the floor panels 2 and 4. Accordingly, the high-rigidity area 72 can be increased greatly by being located properly without having any interference with objects, such as the exhaust pipe and auxiliary components, and with its appropriate height which can provide the passengers with comfortable stepping. Also, since the weight of the area 72 can be increased easily and properly by the plug 66 formed separately, the difference in weight between the heavy-weight area 72 and the light-weight area 74 can be increased properly.
Also, since the difference-in-level portion 62 having bent portions a and b illustrated in
Since the plug 66 according to the first modified example includes the peripheral edge projection 66a projecting at its peripheral downward, this projection 66a further increases the rigidity, particularly the bending and torsional rigidity of the plug 66. As a result, the difference in rigidity between the high-rigidity area 72 and the low-rigidity area 74 can be further increased. Likewise, since the plug 66 according to the second modified example includes the plural beads 66b provided at the upper face thereof, these beads 66b further increase the rigidity of the plug 66. Thus, the difference in rigidity between the high-rigidity area 72 and the low-rigidity area 74 can be further increased. Also, these projection 66a and beads 66b can be made easily by the press forming. Herein, these projection 66a and beads 66b may be integrated with the plug 66 via adhesive or the like.
According to the present embodiment and its modified examples which are described above, the vibration energy at the panel area can be reduced effectively by increasing properly the differences in rigidity and/or weight even though there exists the above-described limitations in vehicle-body structure or manufacturing, such as the heights, dispositions, sizes or the like.
Next, the second embodiment of the present invention will be described specifically referring to
First, the constitution and shape of the panel area S2 and S3 will be described specifically referring to
Next, the vibration reduction structure provided within the panel area S2 will be described specifically referring to
As illustrated in
Next, a first modified example of the present embodiment will be described. The damping material 80 constituting the high-rigidity area (heavy-weight area) 82 may be an asphalt-based damping material. As described above, since the asphalt-based damping material has the approximately 1.7 specific gravity and the approximately 6B pencil-hardness, which is heavier than the application-type of damping material, the great difference in weight between the heavy-weight area 82 and the light-weight area 84 can be obtained particularly.
Next, a second modified example of the present embodiment will be described referring to
Meanwhile, the asphalt-based damping material 86 is heavier than the application-type of damping material 80. Accordingly, in the present modified example, as illustrated in
Next, the function and effect of the floor panel structure according to the second embodiment will be described. Since there are provided the high-rigidity area 82 having the damping material 80 and the low-rigidity area 84 being provided around the high-rigidity area 82 within the panel area S2 and S3, the vibration energy is increased at the low-rigidity area 84 due to the difference in rigidity between the high-rigidity area 82 and the low-rigidity area 84. Further, since the high-rigidity area 82 also constitutes the heavy-weight area 82 which is made heavier per unit area than the peripheral area 84 by the damping material 80, the vibration energy is further increased at the light-weight area (the peripheral area) 84 due to this difference in weight between the heavy-weight area 82 and the light-weight area 84.
The vibration energy being properly increased at the low-rigidity area (light-weight area) 84 is transformed to the thermal energy by the damping effect of the steel plate forming the floor panel 2 and 4. Thus, the vibration energy at the panel area S2 and S3 is reduced, and thereby the acoustic emission generated from the panel area is reduced.
Next, the function and effect of the damping material 80 which constitutes the high-rigidity area (heavy-weight area) 82 will be described. Since the high-rigidity area (heavy-weight area) 82 of the present embodiment has the application-type of damping material 80 having the relatively high hardness of 2H pencil-hardness at the panel area S2 and S3, the greater difference in rigidity between the heavy-weight area 82 and the light-weight area 84 can be obtained. Also, since the heavy-weight area 82 which is heavier than the light-weight area 84 is obtained by the weight of the damping material 80 itself, the greater difference in weight between them can be obtained as well. Further, the vibration energy at the panel area S2 and S3 can be also reduced by the vibration damping function of the damping material 80 itself.
Next, since the damping material 80 constituting the high-rigidity area (heavy-weight area) 82 is made of the asphalt-based damping material which is heavier than the application-type of damping material in the first modified example, the difference in weight between the heavy-weight area (heavy-weight area) 82 and the low-rigidity area (light-weight area) 84 can be provided properly, resulting in the vibration energy being increased properly at the low-rigidity area (light-weight area) 84 by the weight difference.
At the panel area S2 in the second modified example, since the high-rigidity area (heavy-weight area) 82 is comprised of the application-type of damping material 80 having the relatively high hardness (2H pencil-hardness) and the asphalt-based damping material 86 having the relatively low hardness (6B pencil-hardness) is provided at the low-rigidity area (light-weight area) 84, the vibration energy can be reduced by the vibration reduction effect due to the difference in rigidity between the high-rigidity area 82 and the low-rigidity area 84. Also, the vibration energy can be further reduced by the damping function of the application-type of damping material 80 and the asphalt-based damping material 86 themselves.
Meanwhile, since the application-type of damping material 80 at the high-rigidity area (heavy-weight area) 82 is made thicker than the asphalt-based damping material 86 at the low-rigidity area (light-weight area) 84, the weight of the high-rigidity area (heavy-weight area) 82 can be made greater than that of the low-rigidity area (light-weight area) 84 having asphalt-based damping material 86 regardless of the specific gravity of the application-type of damping material 80 (approximately 1.1) being smaller than that of the asphalt-based damping material 86 (approximately 1.7). Thus, the vibration energy can be also reduced by the vibration reduction effect due to the difference in weight between the high-rigidity area (heavy-weight area) 82 and the low-rigidity area (light-weight area) 84 with the asphalt-based damping material 86.
According to the present embodiment and its modified examples which are described above, the vibration energy at the panel area S2 and S3 can be reduced greatly, by providing the damping material 80 and/or the damping material 86 and thereby high-rigidity area (heavy-weight area) 82 and the low-rigidity area (light-weight area (peripheral area)) 84, with the vibration reduction effect due to the differences in rigidity and weight and the damping effect of the damping materials 80 and 86 themselves. Thus, the vibration energy at the panel area can be reduced effectively by the heavy-weight area 82 having heavier weight than the light-weight area (peripheral area) 84 even though there exists the above-described limitations in vehicle-body structure or manufacturing, such as the heights, dispositions, sizes or the like.
Next, the third embodiment of the present invention will be described specifically referring to
First, the constitution and shape of the panel area S13 through S16 will be described specifically referring to
The floor side frame 22 is bent at the connecting portions 29a and 30a with the No. 4 cross member 29 and the No. 5 cross member 30 (bent portions 22b and 22c), so that the floor side frame 22 extend straight between the No. 4 cross member 29 and the No. 5 cross member 30. Herein, the bead 58 functions as the vibration restraint portion to control the vibration area of the panel area S13 or S14, by restraining a vibration linkage between vibration occurring at the panel area S13 or S14 and vibration occurring at the panel area S15 or S16 next to the panel area S13 or S14.
Next, the vibration reduction structure provided within the panel area S13 will be described specifically referring to
As illustrated in
As illustrated in
Next, as illustrated in
Next, the vibration reduction structure provided within the panel area S15 will be described specifically referring to
As illustrated in
As illustrated in
Next, the function and effect of the floor panel structure according to the third embodiment will be described. Since there are provided the high-rigidity area 92 having the increased rigidity by being formed so as to project upward or downward and the low-rigidity area 94 being provided around the high-rigidity area 92 within the panel area S13 through S16, the vibration energy is increased at the low-rigidity area 94 due to the difference in rigidity between the high-rigidity area 92 and the low-rigidity area 94. Further, since the auxiliary component 100 is attached to the high-rigidity area 92 at the panel area S13 and S14, the rigidity of the high-rigidity area 92 is further increased by the auxiliary component 100 to provide the great difference in rigidity.
Further, the high-rigidity area 92 with the auxiliary component 100 also constitutes the heavy-weight area 92 which is made heavier per unit area than the peripheral area 94 by the auxiliary component 100, the difference in weight between the heavy-weight area 92 and the light-weight area 94 is obtained. Also, the weight of the bracket 98 for attaching the auxiliary component 100 increases the weight difference. As a result, the vibration energy is increased at the low-rigidity area (light-weight area) 94 due to the weight difference.
The vibration energy being properly increased at the low-rigidity area (light-weight area) 94 is transformed to the thermal energy by the damping effect of the steel plate forming the floor panel 2 and 4. Thus, the vibration energy at the panel area S13 through S16 is reduced, and thereby the acoustic emission generated from the panel area is reduced. Further, since the damping material 96 is provided at the low-rigidity area (light-weight area) 94, the vibration energy being increased at the low-rigidity area (light-weight area) 94 is reduced properly.
Next, the function and effect of the shape and disposition of the high-rigidity area (heavy-weight area) 92 will be described. According to the present embodiment, since the sides 92a and 92b of the high-rigidity area 92 are formed by the slightly curved lines with the specified curvature, the rigidity changes discontinuously at the sides 92a and 92b of the border of the low-rigidity area 94 and the difference in rigidity between the high-rigidity area 92 and the low-rigidity area 94 can be increased. As a result, the projecting height of the high-rigidity area 92 can be restrained, and the vibration reduction effect can be obtained without having any interference with objects, such as the exhaust pipe and auxiliary components, and with its appropriate height which can provide the passengers with comfortable stepping. Hereinafter, this function and effect will be described more specifically.
There may be case where it is difficult to form the shape of the high-rigidity area accurately when the high-rigidity area with the restrained projecting height is made by applying the press forming to the floor panel. Namely, the press forming applies a plastic deformation to the steal panel, extending the steel panel. Herein, if the projecting height of the panel is restrained to a specified height and the sides of the projection are formed exactly straight, there may be a case where it is difficult to form such a straight bent line properly at the border between the low-rigidity area and the high-rigidity area (at the sides of the high-rigidity area). In this case, as shown in
Meanwhile, in the case where the sides 92a and 92b of the high-rigidity area 92 are formed by the outward slightly curved lines with the specified curvature like the present embodiment, the press forming should be proper. Namely, the border with curved lines allows the bent lines to be formed properly and clearly. In this case, as shown in
Herein, the shorter the side of the border is or the smaller the radius of curvature of the curved side is, the more accurate the press forming is. Since the radius of curvature of the long side 92a is smaller than that of the short side 92b in the present embodiment, the rigidity can change discontinuously at the border surely and the rigidity difference can be made great surely.
Meanwhile, where the curvature radius of the long side 92a extending in the arc shape is small, the long side 92a projects more outwardly toward the low-rigidity area 92, compared with the short side 92b, so that the rigidity of the low-rigidity area 94 might be increased improperly. However, part of the low-rigidity area 94 extending around the long side 92a has its relatively larger area, compared with part of the low-rigidity area 94 extending around the short side 92b. Accordingly, the vibration energy can be increased properly without increasing the rigidity of the above-described part of the low-rigidity area 94 extending around the long side 92a.
Herein, where the high-rigidity area is formed in the circular or oval shape, the rigidity of the high-rigidity area can be changed more discontinuously at the border and its rigidity difference can be increased, but the rigidity of the low-rigidity area may be increased improperly. According to the present embodiment, since the respective sides 92a and 92b of the high-rigidity area 92 are formed by the outward curved lines with the specified curvature and the high-rigidity area 92 is formed in the substantially rectangular shape, the rigidity change at the border can be made discontinuous and the rigidity of the low-rigidity area (light-weight area) 94 extending around the border can be prevented from increasing improperly. Further, since the low-rigidity area 94 is formed with the properly specified width, the vibration energy can be increased intensively and surely at the low-rigidity area (light-weight area) 94.
Since the high-rigidity area 92 at the panel area S15 and S16 contacts the No. 5 cross member 30, the rigidity of the respective high-rigidity area 92 can be increased greatly. Accordingly, where even the panel area has a relatively small entire area and thereby a relatively large rigidity, the rigidity of the high-rigidity area can be increased properly and thus the difference in rigidity between the high-rigidity area 92 and the low-rigidity area 94 can be made great enough, and thereby the vibration energy can be increased surely at the low-rigidity area 94.
Next, the function and effect of the shape of the damping material 96 will be described. Since the damping material 96 includes the opening 96a with the substantially rectangular shape along the outer peripheral edges 92a and 92b of the high-rigidity area 92, by just placing the damping material so that its opening 96a corresponds to the outer peripheral edges 92a and 92b of the high-rigidity area 92, the easy positioning can be obtained and thereby the manufacturing cost can be reduced. Also, since the positing accuracy improves, the damping material 96 can be placed properly without overlapping with the high-rigidity area 92 and the low-rigidity area 94. Thus, the rigidity of the low-rigidity area 94 and the damping material 96 can be prevented from being increased improperly.
According to the present embodiment and its modified examples which are described above, the vibration energy at the panel area can be reduced effectively by increasing properly the differences in rigidity and/or weight between the high-rigidity area 92 and the low-rigidity area 94 even though there exists the above-described limitations in vehicle-body structure or manufacturing, such as the heights, dispositions, sizes or the like.
Next, the fourth embodiment of the present invention will be described specifically referring to
First, the constitution and shape of the vibration transmission reduction structure which is provided at the No. 4 cross member 29 will be described specifically referring to
A rigidity reduction portion 110 is formed at the No. 4 cross member 29 near its connection portion 29b with each of the side sills 20 (see
These recess portions 112c through 112e are connected such that the front recess portion 112c is continuous to the lower recess portion 112e and the lower recess portion 112e is continuous to the rear recess portion 112d. And, the second floor panel 4 is coupled to an upper face (flange) 29f of the No. 4 cross member 29. Herein, an illustration of the second floor panel 4 is omitted in
The rigidity reduction portion 110 is configured such that its rigidity in the vehicle width direction is lower than other portions of the No. 4 cross member 29. Thus, the vibration transmitted to the No. 4 cross member 29 from the side sill 20 is increased intensively at the rigidity reduction portion 110 (recess portion 112) and the vibration is suppressed from being transmitted in the vehicle width direction by the rigidity reduction portion 110, which will be described more in detail below. Also, an application-type damping material 116 is disposed intensively in the space of the recess portions 112c through 112e. This damping material 116 decreases the vibration intensively increased at these recess portions properly and suppresses the transmission of vibration from these recess portions inwardly. The specific gravity and hardness of the application-type of damping material is as described above. Herein, the asphalt-based damping material may be applied instead.
Next, as illustrated in
Further, as illustrated in
Next, the cross section of the connecting portion 29a of the No. 4 cross member 29 with the floor side frame 22, not illustrated, is configured so as to be narrower than the other cross members, thereby suppressing the transmission of vibration from the floor side frame 22. Herein, the rigidity reduction portion 110 may be located near the connecting portion of the floor side frame 22 or at the other members.
Next, the constitution and shape of the panel area S10 and S11 and the vibration reduction structure will be described specifically referring to
As illustrated in
There are provided the substantially rectangular high-rigidity area 92 and the low-rigidity area 94 located around the high-rigidity area 92 within the panel area S10 as illustrated in
As illustrated in
Also, as illustrated in
Next, as illustrated in
As illustrated in
Next, the function and effect of the fourth embodiment will be described. First, the function and effect of the rigidity reduction portion 110 at the No. 4 cross member 29 will be described. Since the rigidity reduction portion 110 which has its lower rigidity than the other portion is provided near the connecting portion 29a of the No. 4 cross member with the side sill 20 according to the present embodiment, the vibration transmitted from the side sill 20 to the No. 4 cross member 29 can be increased at the rigidity reduction portion 110 and the vibration can be prevented properly from being transmitted from this rigidity reduction portion 110 inwardly.
More specifically, where the side sill 20 generates its torsional vibration around a longitudinal axis or its bending vibration in the vertical or lateral directions, such vibration with the torsion or the bending is transmitted to the No. 4 cross member 29. The rigidity reduction portion 110 has its lower rigidity in the vehicle width direction compared with the other portions of the No. 4 cross member 29 as described above, and accordingly it tends to be deformed easily by such vibration with the torsion or bending. Thus, the vibration transmitted from the side sill 20 is increased at this easily-deformable rigidity reduction portion 110 and thereby the vibration from the side sill 20 can be prevented from being transmitted further inwardly from the rigidity reduction portion 110. As a result, the vibration, which will be transmitted to the panel area S10, S11, S13 and S14 via the No. 4 cross member 29, can be reduced properly, and thereby the acoustic emission generated from the floor panel can be reduced.
Hereinafter, the function of the rigidity reduction portion 110 will be described more specifically referring to
When the upper body 122 generate such vibration, the pillars 35 generates a vibration with a laterally-curved deformation as illustrated in
Particularly, since the rigidity reduction portion 110 is formed at the No. 4 cross member 29 which is coupled to the side sills 20, the vibration can be prevented effectively from being transmitted to the No. 4 cross member inwardly where the side sills 20 would generate the torsional vibration with the laterally-inclining deformation due to the bending vibration of the pillars 35 caused by the torsional vibration of the upper body 122. Meanwhile, since the no rigidity reduction portion is provided at the other cross members, such as the No. 3 cross member 28, the sufficiently large rigidity of the vehicle body can be ensured.
Next, the main function and effect of the recess portions 112c and 112d formed at the front and rear feces of the No. 4 cross member 29 will be described. For example, the side sills 20 generates the vibration with laterally-curved deformation when a side force is applied to the suspension from the road surface. This vibration causes the No. 4 cross member 13A to generate a vibration with the bending deformation as illustrated by E in
Next, the function and effect of the recess portions 112c through 112e of the rigidity reduction portion 110 will be described. Where the side sills 20 generate the bending vibration with vertically-curved deformation by the force A illustrated in the figure, there occurs the vibration causing the torsional deformation of the No. 4 cross member 29 illustrated by F in
Next, the function and effect of the damping material 116 provided at the rigidity reduction portion 110 will be described. Sine the damping material 116 is intensively disposed in the space with the arc-shaped cross section of the recess portions 112 in the present embodiment, the vibration intensively increased at the recess portions 112 can be decreased. As a result, the vibration can be prevented from being transmitted from the recess portions 112 inwardly.
Next, the function and effect of the modified example of the rigidity reduction portion 110 will be described. Since the width of the recess portions 112 of the example illustrated in
As described above, according to the present embodiment and the modified example, regardless of the above-described limitations in vehicle-body structure, such as height, locations, size and the like, or manufacturing, the vibration energy at the panel area can be reduced effectively by providing the rigidity reduction portion at the frame member and the like. For example, providing the rigidity reduction portion at the frame member can reduce the vibration transmitted to the floor panels, without having any interference with objects, such as the exhaust pipe and auxiliary components, and with its appropriate height which can provide the passengers with comfortable stepping.
Next, the function and effect of the vibration reduction structure at the panel area S10 and S11 will be described. According to the present embodiment, the rigidity reduction portion 110, as the vibration transmission reduction structure, is provided at the frame member 29 to reduce the vibration transmitted to the panel area, and the high-rigidity area 92 and the low-rigidity area 94, as the vibration reduction structure, are provided within the panel area S10 and S11 to reduce the acoustic emission generated from the floor area S10 and S11.
Since the one side of the high-rigidity area 92 contacts the No. 4 cross member 29 at the panel area S10 and two sides of the high-rigidity area 92 contact the No. 4 cross member 29 and the bent line portion 54 at the panel area S11, the rigidity of the respective high-rigidity area 92 can be increased greatly and thereby the rigidity difference between the high-rigidity area 92 and the low-rigidity area 94 can be further increased. Accordingly, even where the rigidity of the panel area itself is relatively high due to its relatively small area, the difference in rigidity between them can be ensured greatly. Thus, the vibration energy can be increased intensively at the low-rigidity area. Further, the increasing of the vibration energy at the low-rigidity area can be furthered at the panel area S10 by the increased difference in weight between the both area with the bracket 98 and the auxiliary component 100.
Further, since the vibration transmission from the side sills is suppressed properly at the No. 4 cross member 29 the respective high-rigidity area 92 contact as described above, the great vibration can be prevented from being transmitted to the panel area S10 and S11. As a result, the acoustic emission caused by the vibration transmitted to the panel area S10 and S11 from the No. 4 cross member 29 can be reduced, and the vibration reduction effect can be obtained surely by increasing the rigidity of the high-rigidity area 92 properly. Accordingly, regardless of the above-described limitations in vehicle-body structure, such as height, locations, size and the like, or manufacturing, the vibration energy at the panel area can be reduced effectively by the increased rigidity of the heavy-weight area contacting the cross members.
The present invention should not be limited to the above-described embodiments, but any other modifications and improvements may be applied within the scope of a sprit of the present invention.
Hirabayashi, Shigefumi, Sugihara, Tsuyoshi, Nakabayashi, Seiichi
| Patent | Priority | Assignee | Title |
| 11001132, | Jul 20 2016 | Bayerische Motoren Werke Aktiengesellschaft | Motor vehicle |
| D579843, | Sep 20 2007 | NAVISTAR CANADA, INC | Chassis skirt system of a truck vehicle |
| Patent | Priority | Assignee | Title |
| 1624903, | |||
| 2126607, | |||
| 2856226, | |||
| 3638748, | |||
| 4402545, | Feb 27 1980 | Toyo Kogyo Co., Ltd. | Stiffened automobile body structure |
| 5540880, | Aug 12 1987 | Nagoya Oil Chemical Co., Ltd. | Corrosion, sound, and vibration-proof method for metal structure |
| 5635562, | Apr 26 1995 | PERMACEL KANSAS CITY, INC , A MISSOURI CORPORATION | Expandable vibration damping materials |
| 6793276, | Jul 30 2001 | Mazda Motor Corporation | Automobile floor structure |
| 7014256, | Jan 16 2003 | Mazda Motor Corporation | Floor panel structure of vehicle body |
| 7025412, | Aug 26 2003 | Honda Motor Co., Ltd. | Vehicle body structure |
| 20040239150, | |||
| 20050040677, | |||
| DE3837231, | |||
| DE3844145, | |||
| EP1281604, | |||
| JP2003112092, | |||
| JP58218472, | |||
| JP6107235, |
| Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
| Apr 02 2005 | HIRABAYASHI, SHIGEFUMI | Mazda Motor Corporation | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 016554 | /0700 | |
| Apr 08 2005 | SUGIHARA, TSUYOSHI | Mazda Motor Corporation | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 016554 | /0700 | |
| Apr 12 2005 | NAKABAYASHI, SIICHI | Mazda Motor Corporation | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 016554 | /0700 | |
| May 11 2005 | Mazda Motor Corporation | (assignment on the face of the patent) | / |
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